1. Field of the Invention
The present invention relates to an information processing apparatus in a printing system composed of this information processing apparatus and a printing apparatus.
2. Description of the Related Art
A printing system has hitherto been known which comprises a personal computer as a host to which peripheral equipment such as a printing apparatus (printer) capable of execute printing is connected. In the printing system, any application software on the personal computer can cause the printing apparatus to execute printing.
In this printing system, when the application software causes the printing apparatus to execute printing, print data is created as a temporary file. Once the file is completed, the personal computer transmits the print data from this file to the printing apparatus. The printing apparatus then executes printing. Since the printing process can be released from the application software once the temporary file is completely created, the application software can subsequently perform arbitrary operations.
Such a printing process is generally called “spool printing”. In this case, the size of the temporary file corresponds to several dozen to hundred MB of data. Typically, the personal computer comprises a hard disk drive that is a mass storage device that can store several GB of data. The temporary file is created in this hard disk drive. This prevents the situation in which the temporary file cannot be created owing to the insufficiency of an empty area in the hard disk drive.
Such a known printing system is disclosed in, for example, Japanese Patent Application Laid-open Nos. 05-108281, 07-325678, or 2000-168198.
On the other hand, a simplified personal computer (hereinafter also referred to as a “handheld computer”) is known which does not have any mass storage devices such as a hard disk drive. The handheld computer comprises a RAM (Random Access Memory) that can store about several dozen MB. In a printing system having this handheld computer and a printing apparatus, if spool printing is executed, a temporary file for print data is created in the RAM. Consequently, the file is often larger than the empty area in the RAM. As a result, the temporary file cannot be created.
Thus, many handheld computers are configured to directly print all the print data. Specifically, they do not create any temporary files but sequentially transmit part of the print data delivered by application software, to the printing apparatus for printing. However, the printing process cannot be released from the application software until all the print data is transmitted from the handheld computer to the printing apparatus. As a result, it takes a very long time to release the printing process. During this time, the user cannot operate application software.
Further, in handheld computers not configured to directly print all the print data, the empty area in the RAM may run short to prevent the file from being completed. In this case, although the file is partially created, the printing operation is aborted with an error when the empty area becomes insufficient to create the rest of the file. Although the user has been waiting for the printing operation to be finished, the operation is aborted with an error with no print data printed.
For example, Japanese Patent Application Laid-open No. 2002-189574 discloses a known printing system that solves the above problem. This printing system compares the file size of print data with the empty area in the RAM. If the empty area in the RAM is larger, spool printing is executed. Otherwise, direct printing is executed by sequentially transmitting print data.
However, if the file is often larger than the empty area in the RAM, this printing system creates substantially the same problem as that with the above described printing system configured to directly print all the print data. Specifically, if the empty area in the RAM frequently runs short, almost all the data is directly printed. Consequently, the printing process cannot be released from the application software until all the print data is transmitted from the handheld computer to the printing apparatus.